Watching this footage of Egyptian protesters fighting their police show the how different protesting-rioting is when confronting armed police who use live ammunition.
The police are too far away for their petrol bombs being thrown at then to get anywhere near them. Same story with the stones. The protesters however are easily within range of the tear-gas launchers and rubber bullets.
If they get too close, or look like actually hitting the police with firebombs, they would be shot dead.
Contrast this with Greece, where the rioters get very close to the police, routinely hitting officers directly with firebombs.
Greek anarchists think they are tough guys because the work they can expect is tear-gassing and truncheon blows. Egyptian (and Syrian, and Bahraini) protesters risk life and limb to protest.
They are truly brave, unlike their anarchist fellows in Greece.